The effects of in vitro and in vivo (inhalation) exposure to minerals found in association with coal mine dust on function of individual alveolar macrophages will be studied. Dose-response and particle size dependent studies on functional alterations will be conducted using exposure levels which are sublethal to the cells. Two separate techniques will be used to evaluate toxic effects on cells lavaged from male Long Evans hooded rats. Electrophysiological voltage clamp experiments will be used to determine the effect of exposure on plasma membrane permeability to ions and electro-optical techniques will be used to measure the effect on production of superoxide anion, an antibacterial agent produced by cell. In order to correlate functional alteration with exposure to minerals, backscattered electron imaging and X-ray microanalysis will also be performed on individual cells to identify those cells which have phagocytized the minerals. Because functional and electron microscopic evaluation will be done on the same individual cell, correlation between mineral exposure and functional imparement should be improved. Comparison between in vitro and in vivo exposure will permit evaluation of the feasibility of using these in vitro measurements to predict in vivo effects. This interdisciplinary approach should yield important information on the cellular sites of toxicity of minerals and should provide data to aid in assessing risks following inhalation.